The top Community post is an explanation of how to do a workaround just to get the game working again since something broke it, and the developers seemed to have abandoned it.
You have to change it to the "Beta Legacy build" and the dumb part is that none of the quality settings work in that build, nor can I even alt-tab out of the game to change the volume.

I just bought it for Multiplayer and to support the creators.
But the sad truth is that when I tried the cracked version it's much more optimized I can change the volume on the fly, all the settings work, the only downside is no multiplayer, but hey at least the game works.